s390: Enhance test for .insn pseudo-mnemonic rse
Enhances the test for the .insn rse pseudo-mnemonic by documenting its operand order.
This patch enhances the test coverage for the .insn rse pseudo-mnemonic by documenting its operand order, which differs from the standard field index order due to historical reasons. The changes update the s390 assembler’s documentation (gas/doc/c-s390.texi) and improve test cases in gas/testsuite/gas/s390/.
- proposer
Documents the specific operand order for the RSE pseudo-mnemonic and enhances associated tests.
“For historic reasons the .insn rse pseudo-mnemonic operand order differs from the field index order. Document that.”
In Details
This commit addresses a specific aspect of the s390 assembler's .insn directive: the RSE (Register-to-Register, Storage, and Environment) instruction format. It documents that the operand order for the .insn rse pseudo-mnemonic deviates from the general rule of ascending field indices due to historical reasons. The changes involve updating the s390 assembler manual (gas/doc/c-s390.texi) and refining the test cases in gas/testsuite/gas/s390/ to reflect this exception.
- RSE
- A s390 instruction format (Register-to-Register, Storage, and Environment).
- .insn
- An assembler directive used to specify machine instructions directly, often with pseudo-mnemonics.
- field index order
- The standard order of operands based on their numerical field indices in the instruction format, as defined in architecture manuals.